基于平行板电容式湿度传感器动态特性模型研究

摘要

依据菲克第二扩散定律、Shibata和Looyenga等方程,并引入有效扩散系数和孔隙率的关系式,以考虑感湿膜孔隙率对湿敏元件响应特性的影响,创建了一个数值模型.通过实验结果和模拟结果的对比分析,验证了所述数值模型及数值方法用于湿敏元件动态特性研究的可行性.最后利用模型,借助Fluent软件对高分子栅状上电极平行板湿敏元件动态响应特性进行了数值研究,根据对模拟结果分析,发现有效扩散系数和孔隙率是制约湿敏元件动态性能的关键参数,合理增大膜孔隙率可进一步改善湿敏元件动态响应特性.同时,该模型能够揭示电容式湿敏元件结构参数,模拟结果可为微型湿敏元件动态特性的进一步研究提供借鉴.%According to Fick`s second law of diffusion, the Shibata and Looyenga equation, effective diffusion coefficient and the relation between the porosity were introduced,and a new model considering the porosity effects of the polymer film on the dynamic characteristics was presented.By comparing the experimental results and the analysis of the simulation results, the numerical model and numerical method for the feasibility study of the dynamic characteristics of the humidity sensor were veryfied.At last, with the help of model, software Fluent was used to research parameter effects on the response time of the humidity sensor based on the grid upper electrode were studied by the numerical method.According to the results of simulation analysis, it is found that the effective diffusion coefficient and the porosity are the key to restricting the moisture sensor dynamic performance parameters.Reasonable increase membrane porosity can further improve the moisture sensor dynamic response.At the same time, the model can reveal the capacitive moisture sensor structure parameters, the simulation results provide reference for further research for the dynamic characteristics of the micro moisture sensor.